Crippled by his wounds at Saratoga, Benedict Arnold was put in charge of Philadelphia. There, he began to socialize with families loyal to the British. He also took to an extravagant life with lavish expenditures, which he financed with questionable methods that led to scandal. Arnold also married a much younger woman of loyalist sympathies and spendthrift habits, that soon drove him into deep indebtedness. Between resentments and financial difficulties, he secretly approached the British to offer his services. Arnold was well positioned to deal the Patriots a fatal blow, because he was placed in charge of colonial fortifications at West Point on the Hudson River, that lay upstream from British-occupied New York City and barred them from sailing upriver.
Arnold plotted to sell plans of the fortifications to the enemy, and contrived to deliver them into British hands for Â£20,000. However, his British contact was captured, along with documents that incriminated Arnold. He fled just in time to evade arrest. He was made a brigadier general in the British Army, and led soldiers against the Patriots for the rest of the war. The British never fully warmed to him however, and he was unable to secure a regular commission after the war. He pursued a variety of ventures, including privateering and land speculation in Canada, before he finally settled down in London, where he died in 1801.
Where Did We Find This Stuff? Some Sources and Further Reading